There's growing evidence that the number of great white sharks is on the rise along Canada's East Coast, where plans are in the works to post warning signs for beachgoers for the first time.
Fred Whoriskey, director of the Ocean Tracking Network at Dalhousie University in Halifax, says the population of these apex predators appears to be growing because of successful conservation measures and a rapidly growing food supply, mainly grey seals.
"We're probably seeing more animals here, though we don't know how many," he said in an interview.
"No one has a handle on the northwest Atlantic white shark population .... (But) I've spoken to a lot of lobstermen who are seeing things that they have not seen for 40, 50 years on the water. That would suggest (the sharks) are reoccupying areas they have been away from."
The North Atlantic shark population has been protected in Canada since 2011 and in the United States since 1994. Those protections were introduced after studies showed the population had declined by as much as 80 per cent as fishing increased in the 1970s and 1980s.
Now they're making a comeback.
Aside from more frequent sightings, there have been reports in Nova Scotia of two attacks in recent years, one of which injured a swimmer and another that killed a dog. As well, warning signs and flags have already been installed at beaches in Massachusetts and Maine following two fatal shark attacks, one in 2018 at Cape Cod and another in 2020 at Maine's Casco Bay.
In Nova Scotia, the plan is to install warning signs at about a dozen public beaches as early as this summer. But they probably won't look like the American versions, which often feature an arresting image of a great white shark, its sharp teeth and unblinking eyes the stuff of nightmares.
That kind of high-profile sign would be prone to theft and vandalism, Whoriskey said. That's why he wants to install smaller signs with QR codes that will allow smartphone users to download detailed information.
"It's good to inform yourself (about the risks), in the same way that we inform ourselves about traffic safety," he said. "Getting this information out to minimize conflicts between humans and wildlife is always a good thing."
Whoriskey is working with the non-profit Lifesaving Society of Nova Scotia, which oversees the lifeguards who supervise about 20 beaches during the summer. Each season, up to 500,000 people visit those beaches.
Among other things, the website will tell people not to swim alone or near seals, and to avoid swimming at dawn, dusk and at night, prime feeding times for great whites.
Shark expert John Chisholm, a scientist at the New England Aquarium in Boston, says the attacks in New England prompted officials to launch public awareness campaigns, install warning signs and roll out a shark-tracking app called Sharktivity.
"We know from our experience down here that people were unaware how close the sharks come in when they're hunting seals or feeding on fish," said Chisholm, who has been studying white sharks since the late 1970s.
"We know that a lot of the white sharks that we tag go up to Canadian waters, all the way into the Bay of Fundy, the Cabot Strait, the Gulf of St. Lawrence and all the way over to Quebec. That's white shark habitat and people need to be aware of it .... They've always been there and they're becoming more abundant."
As early as 2014, a comprehensive study from the U.S. National Oceanic and Atmospheric Administration concluded the white shark population was surging in the ocean off the eastern United States and Canada.
Public concern in Atlantic Canada spiked in August 2021 when the RCMP in western Cape Breton reported that a 21-year-old woman had allegedly been bitten by a shark while swimming near Margaree Island.
According to published reports, the woman was airlifted to hospital to get stitches on her thigh. But an entry in the Canadian Shark Attack Registry says no one came forward to provide evidence.
Then in October 2023, an anonymous hunter reported that a shark had killed his dog as it was retrieving a sea duck close to shore, near Port Medway, N.S.
“It happened so quickly and was so shocking that even though I was looking right at her when it happened, I cannot say for certain what type of shark it was,” the owner said in a statement, adding that the fish was about 2.4 metres long.
Whoriskey said many of the sharks showing up in Canadian waters are juveniles and subadults that are making the transition from feeding on fish to eating larger prey, like seals.
"Those individuals pass through a learning phase," he said. "If we get a lot of those, then there's a probability of close encounters that could include humans."
According to the St. Lawrence Shark Observatory, which maintains the attack registry, the last time someone was killed by a shark in Canadian waters was July 1953, when a shark rammed a lobster boat, causing it to capsize. One of the men aboard drowned but wasn't bitten.
"The fact is that we are not a preferred prey item, otherwise you would have seen a lot more mortality from white sharks," Whoriskey said.
Still, Stephen Crawford has been advocating for warning signs and accompanying shark-bite trauma kits for years.
"I think that wherever any wild animals pose a risk to human life, the humans entering those wild environments have a moral and legal right to know what the risk of danger is," said Crawford, a professor of integrative biology at the University of Guelph.
As an example, he cited Parks Canada's online bulletins, brochures and warning signs about rattlesnakes, coyotes and bears.
Meanwhile, Parks Canada says it has no plans to install shark signs on the beaches it oversees.
"Atlantic white sharks are an endangered species; therefore, the likelihood of seeing a shark, let alone an encounter, are very low," Parks Canada spokesman Adam Young said in an email.
Crawford said that approach is misguided, given that the species' endangered status is based on limited data.
"According to Indigenous and local experts ... I've spoken to from Maine to Quebec, the annual white shark migration has increased dramatically over the past 10 years," he said, adding that warning signs should be placed in all four Atlantic provinces and Quebec.
This report by The Canadian Press was first published June 16, 2024.
